TY - JOUR
T1 - Improved technique for measurement of regional fractional ventilation by hyperpolarized3He MRI
AU - Emami, Kiarash
AU - Kadlecek, Stephen J.
AU - Woodburn, John M.
AU - Zhu, Jianliang
AU - Yu, Jiangsheng
AU - Vahdat, Vahid
AU - Pickup, Stephen
AU - Ishii, Masaru
AU - Rizi, Rahim R.
PY - 2010/1
Y1 - 2010/1
N2 - Quantitative measurement of regional lung ventilation is of great significance in assessment of lung function in many obstructive and restrictive pulmonary diseases. A new technique for regional measurement of fractional ventilation using hyperpolarized 3He MRI is proposed, addressing the shortcomings of an earlier approach that limited its use to small animals. The new approach allows for the acquisition of similar quantitative maps over a shortened period and requires substantially less 3He gas. This technique is therefore a better platform for implementation in large species, including humans. The measurements using the two approaches were comparable to a great degree, as verified in a healthy rat lung, and are very reproducible. Preliminary validation is performed in a lung phantom system. Volume dependency of measurements was assessed both in vivo and in vitro. A scheme for selecting an optimum flip angle is proposed. In addition, a dead space modeling approach is proposed to yield more accurate measurements of regional fractional ventilation using either method. Finally, sensitivity of the new technique to model parameters, noise, and number of included images were assessed numerically. As a prelude to application in humans, the technique was implemented in a large animal study successfully.
AB - Quantitative measurement of regional lung ventilation is of great significance in assessment of lung function in many obstructive and restrictive pulmonary diseases. A new technique for regional measurement of fractional ventilation using hyperpolarized 3He MRI is proposed, addressing the shortcomings of an earlier approach that limited its use to small animals. The new approach allows for the acquisition of similar quantitative maps over a shortened period and requires substantially less 3He gas. This technique is therefore a better platform for implementation in large species, including humans. The measurements using the two approaches were comparable to a great degree, as verified in a healthy rat lung, and are very reproducible. Preliminary validation is performed in a lung phantom system. Volume dependency of measurements was assessed both in vivo and in vitro. A scheme for selecting an optimum flip angle is proposed. In addition, a dead space modeling approach is proposed to yield more accurate measurements of regional fractional ventilation using either method. Finally, sensitivity of the new technique to model parameters, noise, and number of included images were assessed numerically. As a prelude to application in humans, the technique was implemented in a large animal study successfully.
KW - Fractional ventilation
KW - Hyperpolarized gas MRI
KW - Mathematical models of lung
KW - Quantitative pulmonary imaging
KW - Regional lung ventilation
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U2 - 10.1002/mrm.22186
DO - 10.1002/mrm.22186
M3 - Article
C2 - 19877277
AN - SCOPUS:73349137582
SN - 0740-3194
VL - 63
SP - 137
EP - 150
JO - Magnetic resonance in medicine
JF - Magnetic resonance in medicine
IS - 1
ER -